Manufacturing method of impeller

Abstract

A manufacturing method of an impeller includes forming a plurality of blades integrally on a blade attachment surface of one of a disc and a cover, placing the cover on a floor so as to face up the blade attachment surface of the cover, disposing the disc on the cover so as to face down the blade attachment surface of the disc, and bonding the plurality of blades to the blade attachment surface of the other of the disc and the cover which is not formed integrally with the plurality of blades by using a bonding material.

What is claimed is: 
     
       1. A manufacturing method of an impeller, which includes a disc, a cover opposed to the disc, a plurality of blades between the disc and the cover, and a plurality of passages between the disc and the cover, each of the plurality of passages having an inlet on a surface of the cover of the impeller and an outlet on an outer peripheral surface of the impeller, and the direction of each of the plurality of passages being changed so as to follow a radial direction of the impeller as each of the plurality of passages proceeds from the inlet to the outlet, the manufacturing method comprising:
 forming the plurality of blades integrally on a blade attachment surface of one of the disc and the cover; 
 placing the cover on a floor so that the blade attachment surface of the cover faces in an upward direction; 
 disposing the disc on the cover so the blade attachment surface of the disc faces in a downward direction; 
 bonding the plurality of blades to the blade attachment surface of the other of the disc and the cover which is not formed integrally with the plurality of blades using a bonding material; and 
 for each passage of the plurality of passages, forming an uneven portion proximal to an inner peripheral bond part end at a curved portion of the passage, in a bond part with the blades, on the blade attachment surface of the cover so as to prevent the bonding material from spilling. 
 
     
     
       2. The manufacturing method according to  claim 1 , wherein the uneven portion is a protruding portion or a recess portion. 
     
     
       3. The manufacturing method according to  claim 2 , wherein a surface opposite to the blade attachment surface of the cover is flat, and after the plurality of blades is joined to one of the disc and the cover, the surface opposite to the blade attachment surface of the cover is formed into a predetermined shape. 
     
     
       4. The manufacturing method according to  claim 1 , wherein a surface opposite to the blade attachment surface of the cover is flat, and after the plurality of blades is joined to one of the disc and the cover, the surface opposite to the blade attachment surface of the cover is formed into a predetermined shape. 
     
     
       5. The manufacturing method according to  claim 1 , wherein the uneven portion is a protruding portion. 
     
     
       6. The manufacturing method according to  claim 5 , wherein a length of the protruding portion is equal to or greater than a width of the blade. 
     
     
       7. The manufacturing method according to  claim 5 , further comprising removing the protruding portion after said bonding. 
     
     
       8. The manufacturing method according to  claim 1 , wherein the uneven portion is a recess portion. 
     
     
       9. The manufacturing method according to  claim 8 , wherein a length of the recess portion is equal to or greater than a width of the blade. 
     
     
       10. The manufacturing method according to  claim 1 , wherein during said bonding, the bonding material flows toward the inner peripheral bond end part.